Derek - What we have done on 4 trips to the Atlas is to stay a night at a house/small hotel, then leave what we don't want there, to pick up on our return. Very cheap, reliable, supports local economies and gets one off to a good start - and nice to come back to at the end. But this may not fit with your plans, I know.
Re waste of fuel priming stoves (and again, less feasible for you on this trip), we tend to use meths as a primer, which means you can start cooking straightaway.
On one trip, we used a hexi stove, which worked well, especially as we slept under the stars almost entirely. Another trip we got paraffin in Gib, to save time and hassle in Morocco.
Some information from Hamish Brown gives the glimmer of a final plan. Hamish says "out the back of Hotel Ali there is an ironmongers who sells pieceable cartridges. So plan 5 : book a night in Hotel Ali just before we fly back and ensure in the same email that we can leave a bag there while we are gone. Fly in to Marakesh with a gas and a petrol stove, find the ironmonger, if not ask at hotel Ali, buy gas if available, petrol if not. Leave the other stove at hotel Ali. Bus out to Amezmiz the same day to start our trek. Return for the last night or before and pick up our stuff.
Sounds like a win-win. One thing, if they are "piercable" cartridges, are they the Camping Gaz type? If so, then I believe threaded burners (like the MSR Pocket Rocket etc) won't fit without an adaptor. Sounds like Hamish would know.